/* ============================================================================
   LaTeX → Word · V3 设计系统
   理念：学术底蕴 × 现代交互 × 玻璃质感
   ============================================================================ */

/* --------------------------------------------------------------------------
   CSS Variables
   -------------------------------------------------------------------------- */
:root {
    /* 牛津学术色板 */
    --ink: #1a1410;
    --ink-light: #5c4f43;
    --paper: #fdfaf4;
    --paper-dark: #f5efe0;
    --navy: #6b1d2a;
    --navy-light: #8b2e3a;
    --gold: #9b7d3c;
    --gold-light: #c4a35a;
    --border: #e0d7c6;
    --border-dark: #b8a88c;
    --success: #4a6741;
    --error: #9b2c2c;
    --warning: #b7791f;
    --radius: 8px;
    --radius-sm: 4px;
    --radius-lg: 14px;
    --radius-xl: 20px;
    --shadow-sm: 0 1px 2px rgba(26,20,16,.05);
    --shadow-md: 0 4px 16px rgba(26,20,16,.07),0 1px 3px rgba(26,20,16,.04);
    --shadow-lg: 0 12px 40px rgba(26,20,16,.1),0 4px 12px rgba(26,20,16,.05);
    --shadow-glow: 0 0 0 3px rgba(107,29,42,.12);
    --font-display: 'Georgia','Times New Roman','Noto Serif SC','SimSun',serif;
    --font-body: 'Georgia','Palatino','Book Antiqua','Noto Serif SC','PingFang SC','Microsoft YaHei',serif;
    --font-mono: 'JetBrains Mono','Cascadia Code','Consolas','SF Mono',monospace;
    --ease: cubic-bezier(.4,0,.2,1);
    --ease-bounce: cubic-bezier(.34,1.56,.64,1);
    --ease-spring: cubic-bezier(.22,.98,.46,1.01);
    --glass-bg: rgba(253,250,244,.85);
    --glass-border: rgba(26,20,16,.06);
    --glass-shadow: 0 8px 32px rgba(26,20,16,.05);
    --blur: blur(20px);
}

/* --------------------------------------------------------------------------
   Reset & Base
   -------------------------------------------------------------------------- */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}

html{font-size:16px;-webkit-font-smoothing:antialiased;scroll-behavior:smooth}

body{
    font-family:var(--font-body);
    font-size:15px;
    background:#f5f0e6;
    color:var(--ink);
    line-height:1.7;
    min-height:100vh;
    display:flex;flex-direction:column;
    overflow-x:hidden;
}

/* Animated gradient background — warm parchment glow */
body::before{
    content:'';position:fixed;inset:0;z-index:0;pointer-events:none;
    background:
        radial-gradient(ellipse 80% 60% at 20% 10%,rgba(107,29,42,.04) 0%,transparent 55%),
        radial-gradient(ellipse 60% 80% at 80% 90%,rgba(155,125,60,.05) 0%,transparent 55%),
        radial-gradient(ellipse 40% 40% at 50% 50%,rgba(74,103,65,.03) 0%,transparent 50%);
    animation:bgShift 20s ease-in-out infinite alternate;
}
@keyframes bgShift{
    0%{opacity:.6;transform:scale(1)}
    100%{opacity:1;transform:scale(1.05)}
}

/* Grid overlay texture */
body::after{
    content:'';position:fixed;inset:0;z-index:0;pointer-events:none;opacity:.015;
    background-image:
        linear-gradient(rgba(26,51,80,.3) 1px,transparent 1px),
        linear-gradient(90deg,rgba(26,51,80,.3) 1px,transparent 1px);
    background-size:60px 60px;
}

/* --------------------------------------------------------------------------
   Top Bar
   -------------------------------------------------------------------------- */
.topbar{
    background:linear-gradient(135deg,#4a1520,#6b1d2a);
    color:rgba(255,255,255,.88);
    padding:8px 0;
    font-size:13px;
    position:sticky;top:0;z-index:100;
    backdrop-filter:var(--blur);
    border-bottom:1px solid rgba(255,255,255,.08);
}
.topbar-inner{
    max-width:1120px;margin:0 auto;padding:0 28px;
    display:flex;justify-content:space-between;align-items:center;
}
.topbar-brand{
    font-family:var(--font-display);font-style:italic;
    font-size:16px;color:var(--gold-light);letter-spacing:.5px;
    display:flex;align-items:center;gap:8px;
}
.topbar-version{
    font-family:var(--font-mono);font-size:10px;
    background:rgba(255,255,255,.1);padding:2px 8px;border-radius:10px;
}

/* --------------------------------------------------------------------------
   Header — Hero Section
   -------------------------------------------------------------------------- */
.header{
    background:linear-gradient(180deg,#3d1018 0%,#6b1d2a 50%,#4a1520 100%);
    color:var(--paper);padding:60px 0 72px;text-align:center;
    position:relative;z-index:1;overflow:hidden;
}
.header::before{
    content:'';position:absolute;inset:0;
    background:radial-gradient(ellipse 60% 100% at 50% 100%,rgba(184,134,11,.15) 0%,transparent 60%);
}
.header::after{
    content:'';display:block;width:80px;height:2px;
    background:linear-gradient(90deg,transparent,var(--gold),transparent);
    margin:28px auto 0;
}
.header h1{
    font-family:var(--font-display);font-size:48px;font-weight:400;
    letter-spacing:1px;margin-bottom:12px;position:relative;
}
.header h1 .accent{color:var(--gold-light);font-style:italic;position:relative}
.header h1 .accent::after{
    content:'';position:absolute;bottom:2px;left:0;right:0;height:3px;
    background:var(--gold);opacity:.3;border-radius:2px;
}
.header .subtitle{
    font-size:16px;color:rgba(255,255,255,.5);font-weight:400;
    max-width:600px;margin:0 auto;position:relative;
}

/* Floating particles */
.header .particle{
    position:absolute;border-radius:50%;pointer-events:none;
    background:rgba(196,163,90,.15);animation:float 6s ease-in-out infinite;
}
@keyframes float{
    0%,100%{transform:translateY(0) scale(1)}
    50%{transform:translateY(-20px) scale(1.2)}
}

/* --------------------------------------------------------------------------
   Main Layout
   -------------------------------------------------------------------------- */
.main{flex:1;padding:40px 0 80px;position:relative;z-index:1}
.container{max-width:1120px;margin:0 auto;padding:0 28px}

/* --------------------------------------------------------------------------
   Glass Card Base
   -------------------------------------------------------------------------- */
.card-glass{
    background:var(--glass-bg);backdrop-filter:var(--blur);
    border:1px solid var(--glass-border);border-radius:var(--radius-lg);
    box-shadow:var(--glass-shadow);transition:all .3s var(--ease);
}
.card-glass:hover{box-shadow:var(--shadow-md);transform:translateY(-1px)}

/* --------------------------------------------------------------------------
   Quota Bar
   -------------------------------------------------------------------------- */
.quota-bar{
    display:flex;justify-content:space-between;align-items:center;
    padding:12px 20px;margin-bottom:20px;
    background:var(--glass-bg);backdrop-filter:var(--blur);
    border:1px solid var(--glass-border);border-radius:var(--radius-lg);
    transition:all .3s var(--ease);
}
.quota-text{font-size:14px;color:var(--navy);font-weight:500}

/* --------------------------------------------------------------------------
   Tab Bar — Modern Pill Design
   -------------------------------------------------------------------------- */
.tab-bar{
    display:flex;gap:4px;margin-bottom:20px;
    background:rgba(0,0,0,.03);padding:4px;border-radius:var(--radius-lg);
}
.tab-btn{
    font-family:var(--font-body);font-size:14px;font-weight:500;
    padding:10px 24px;border:none;border-radius:var(--radius);cursor:pointer;
    color:var(--ink-light);background:transparent;
    transition:all .25s var(--ease);white-space:nowrap;
    letter-spacing:.3px;
}
.tab-btn:hover{color:var(--navy);background:rgba(255,255,255,.5)}
.tab-btn.active{
    color:var(--navy);background:#fff;box-shadow:var(--shadow-sm);font-weight:600;
}

.tab-panel{display:none;animation:fadeSlideIn .4s var(--ease)}
.tab-panel.active{display:block}
@keyframes fadeSlideIn{
    from{opacity:0;transform:translateY(8px)}
    to{opacity:1;transform:translateY(0)}
}

/* --------------------------------------------------------------------------
   Textarea — Modern Input
   -------------------------------------------------------------------------- */
textarea#latexInput,textarea#aiTextInput{
    width:100%;min-height:260px;padding:20px 24px;
    border:1.5px solid var(--border);border-radius:var(--radius-lg);
    font-family:var(--font-mono);font-size:14px;line-height:1.9;
    color:var(--ink);background:#fdfdfc;
    resize:vertical;outline:none;
    transition:all .25s var(--ease);
}
textarea#latexInput:focus,textarea#aiTextInput:focus{
    border-color:var(--navy);box-shadow:var(--shadow-glow);
    background:#fff;
}
textarea#latexInput::placeholder,textarea#aiTextInput::placeholder{
    color:#c4b99a;font-family:var(--font-body);font-size:14px;font-style:italic;
}

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */
.btn{
    display:inline-flex;align-items:center;gap:8px;
    padding:12px 28px;font-size:14px;font-weight:600;
    font-family:var(--font-body);letter-spacing:.3px;
    border:none;border-radius:var(--radius);cursor:pointer;
    transition:all .25s var(--ease);position:relative;overflow:hidden;
}
.btn::after{
    content:'';position:absolute;inset:0;background:rgba(255,255,255,.1);
    opacity:0;transition:opacity .2s;
}
.btn:hover::after{opacity:1}
.btn:active{transform:scale(.97)}

.btn-primary{background:var(--navy);color:#fff}
.btn-primary:hover{box-shadow:0 4px 20px rgba(26,51,80,.3);transform:translateY(-1px)}
.btn-primary:disabled{background:#b0b8c0;cursor:not-allowed;transform:none;box-shadow:none}

.btn-secondary{background:transparent;color:var(--navy);border:1.5px solid var(--border-dark)}
.btn-secondary:hover{border-color:var(--navy);background:rgba(26,51,80,.04)}

.btn-sm{padding:7px 16px;font-size:12px}
.btn-outline{
    background:transparent;color:var(--gold-light);
    border:1px solid rgba(212,168,83,.3);font-size:12px;
    padding:5px 14px;border-radius:var(--radius);cursor:pointer;
    transition:all .2s;font-family:var(--font-display);
}
.btn-outline:hover{background:rgba(212,168,83,.1);border-color:var(--gold)}

/* Format Select */
.format-select{
    font-family:var(--font-body);font-size:14px;font-weight:500;
    color:var(--navy);background:var(--paper);
    border:1.5px solid var(--border-dark);border-radius:var(--radius);
    padding:12px 40px 12px 16px;cursor:pointer;
    appearance:none;-webkit-appearance:none;
    background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%231a3350' stroke-width='1.5' fill='none'/%3E%3C/svg%3E");
    background-repeat:no-repeat;background-position:right 14px center;
    transition:all .2s var(--ease);outline:none;
}
.format-select:focus{border-color:var(--navy);box-shadow:var(--shadow-glow)}

/* --------------------------------------------------------------------------
   File Drop Zone — Interactive Drag & Drop
   -------------------------------------------------------------------------- */
.file-drop-zone{
    border:2px dashed var(--border-dark);border-radius:var(--radius-lg);
    padding:48px 24px;text-align:center;cursor:pointer;
    transition:all .3s var(--ease);background:rgba(253,252,249,.5);
    position:relative;overflow:hidden;
}
.file-drop-zone::before{
    content:'';position:absolute;inset:-2px;border-radius:inherit;
    background:linear-gradient(135deg,var(--navy),var(--gold));opacity:0;
    transition:opacity .3s;z-index:-1;
}
.file-drop-zone.drag-over{
    border-color:var(--navy);background:rgba(26,51,80,.03);
    transform:scale(1.01);
}
.file-drop-zone.drag-over::before{opacity:.15}
.file-drop-zone .drop-icon{font-size:48px;margin-bottom:12px;transition:transform .3s var(--ease-bounce)}
.file-drop-zone.drag-over .drop-icon{transform:scale(1.1) translateY(-4px)}
.file-drop-zone .file-icon{
    display:inline-block;font-family:var(--font-mono);font-size:20px;font-weight:700;
    color:var(--navy);background:rgba(107,29,42,.06);padding:8px 16px;border-radius:var(--radius);
    margin-bottom:12px
}
.file-drop-zone .file-hint{color:var(--ink-light);line-height:1.8}
.file-drop-zone .file-hint strong{color:var(--navy)}

/* --------------------------------------------------------------------------
   Demo Cards — Organized Grid
   -------------------------------------------------------------------------- */
.demo-cards-section{
    margin-top:20px;padding:24px;
    background:var(--glass-bg);backdrop-filter:var(--blur);
    border:1px solid var(--glass-border);border-radius:var(--radius-xl);
}
.demo-section-header{display:flex;align-items:center;gap:10px;margin-bottom:6px}
.demo-section-title{font-family:var(--font-display);font-size:15px;color:var(--navy);font-weight:600;letter-spacing:.3px}
.demo-section-badge{font-size:10px;padding:3px 10px;border-radius:12px;background:rgba(45,106,79,.1);color:var(--success);font-weight:600}
.demo-section-desc{font-size:12px;color:var(--ink-light);margin:0 0 14px 0;line-height:1.5}

.demo-cards-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:14px}

/* Category divider */
.demo-category{
    grid-column:1/-1;display:flex;align-items:baseline;gap:10px;
    padding:8px 0 4px;margin-top:4px
}
.demo-category:first-child{margin-top:0}
.demo-category-label{font-size:13px;color:var(--navy);font-weight:700;letter-spacing:.3px}
.demo-category-hint{font-size:11px;color:var(--ink-light)}

/* Standard card */
.demo-card{
    background:#fff;border:1px solid var(--border);border-radius:var(--radius-lg);
    padding:18px 20px;cursor:pointer;transition:all .25s var(--ease);
    display:flex;flex-direction:column;gap:8px;
}
.demo-card:hover{border-color:var(--navy);box-shadow:var(--shadow-md);transform:translateY(-2px)}
.demo-card-top{display:flex;align-items:center;justify-content:space-between}
.demo-card-level{font-size:10px;color:#fff;padding:2px 10px;border-radius:4px;font-weight:600;letter-spacing:.3px}
.demo-card-free{font-size:10px;padding:2px 8px;border-radius:4px;background:rgba(45,106,79,.08);color:var(--success);font-weight:500}
.demo-card-name{font-size:14px;font-weight:600;color:var(--ink);margin:0;line-height:1.3}
.demo-card-desc{font-size:12px;color:var(--ink-light);line-height:1.5;margin:0;flex:1}
.demo-card-meta{display:flex;gap:14px;font-size:11px;color:var(--ink-light)}
.demo-card-cost{font-family:var(--font-mono)}

/* Card actions row */
.demo-card-actions{
    display:flex;align-items:center;justify-content:space-between;
    margin-top:4px;gap:8px
}
.demo-card-btn{
    font-size:13px;color:var(--navy);font-weight:600;cursor:pointer;
    transition:color .2s,transform .2s
}
.demo-card:hover .demo-card-btn{color:var(--navy-light)}
.demo-card-dl-btn{
    display:inline-flex;align-items:center;gap:4px;
    font-size:11px;font-weight:600;color:var(--navy);
    background:rgba(26,51,80,.06);padding:6px 14px;border-radius:20px;
    text-decoration:none;transition:all .2s var(--ease)
}
.demo-card-dl-btn:hover{background:var(--navy);color:#fff;transform:scale(1.05)}
.demo-card-source{
    font-size:16px;text-decoration:none;opacity:.4;transition:opacity .15s;line-height:1
}
.demo-card-source:hover{opacity:1}

/* Reference card — premium highlight */
.demo-card-ref{
    border:2px solid var(--gold);background:linear-gradient(135deg,#fffdf7,#fff);
    box-shadow:0 2px 16px rgba(184,134,11,.08);
    grid-column:1/-1;max-width:100%
}
.demo-card-ref:hover{border-color:var(--gold-light);box-shadow:0 4px 24px rgba(184,134,11,.15)}
.demo-card-ref .demo-card-name{font-size:16px}
.demo-card-ref .demo-card-dl-btn{background:var(--navy);color:#fff;padding:7px 16px}
.demo-card-ref .demo-card-dl-btn:hover{background:var(--navy-light)}
.demo-card-ref .demo-card-btn{font-size:14px;color:var(--navy);font-weight:700}
.demo-card-ref .demo-card-btn::after{content:' \2192'}

/* Skeleton */
.demo-card-skeleton{padding:20px;background:#fff;border:1px solid var(--border);border-radius:var(--radius-lg)}
.demo-card-empty{grid-column:1/-1;text-align:center;padding:24px;color:var(--ink-light);font-size:13px}

/* --------------------------------------------------------------------------
   Toast Notification System
   -------------------------------------------------------------------------- */
.toast-container{position:fixed;top:80px;right:24px;z-index:9999;display:flex;flex-direction:column;gap:8px}
.toast{
    padding:14px 20px;border-radius:var(--radius-lg);font-size:14px;font-weight:500;
    color:#fff;box-shadow:var(--shadow-lg);min-width:280px;max-width:420px;
    animation:toastIn .4s var(--ease-spring);cursor:pointer;
    display:flex;align-items:center;gap:10px;
    backdrop-filter:var(--blur);
}
.toast.removing{animation:toastOut .3s var(--ease) forwards}
@keyframes toastIn{from{opacity:0;transform:translateX(100%)}to{opacity:1;transform:translateX(0)}}
@keyframes toastOut{to{opacity:0;transform:translateX(100%)}}
.toast.success{background:linear-gradient(135deg,#4a6741,#2d4a28)}
.toast.error{background:linear-gradient(135deg,#9b2c2c,#6b1d2a)}
.toast.info{background:linear-gradient(135deg,#6b1d2a,#3d1018)}
.toast .toast-icon{font-size:20px;flex-shrink:0}

/* --------------------------------------------------------------------------
   Loading Skeleton
   -------------------------------------------------------------------------- */
.skeleton{background:linear-gradient(90deg,var(--border) 25%,var(--border-light,.5) 50%,var(--border) 75%);background-size:200% 100%;animation:shimmer 1.5s ease-in-out infinite;border-radius:var(--radius)}
@keyframes shimmer{0%{background-position:200% 0}100%{background-position:-200% 0}}

/* --------------------------------------------------------------------------
   Progress Bar
   -------------------------------------------------------------------------- */
.progress-bar{
    height:4px;background:var(--border);border-radius:2px;overflow:hidden;margin-top:12px
}
.progress-bar .fill{
    height:100%;background:linear-gradient(90deg,#6b1d2a,#8b2e3a,#9b7d3c);
    border-radius:2px;transition:width .3s var(--ease);animation:progressPulse 1.5s ease-in-out infinite
}
@keyframes progressPulse{0%,100%{opacity:1}50%{opacity:.7}}

/* --------------------------------------------------------------------------
   Modal
   -------------------------------------------------------------------------- */
.modal-overlay{
    display:none;position:fixed;inset:0;z-index:200;
    background:rgba(26,29,35,.5);backdrop-filter:blur(4px);
    align-items:center;justify-content:center;
}
.modal-overlay.visible{display:flex;animation:fadeIn .25s var(--ease)}
.modal-card{
    background:var(--paper);border-radius:var(--radius-xl);padding:40px 36px 36px;
    max-width:460px;width:90%;position:relative;
    box-shadow:var(--shadow-lg);animation:modalIn .3s var(--ease-spring);
}
@keyframes modalIn{from{opacity:0;transform:translateY(12px) scale(.95)}to{opacity:1;transform:translateY(0) scale(1)}}
@keyframes fadeIn{from{opacity:0}to{opacity:1}}

.modal-close{
    position:absolute;top:16px;right:20px;background:none;border:none;
    font-size:24px;color:var(--ink-light);cursor:pointer;opacity:.5;
    transition:all .2s;width:36px;height:36px;border-radius:50%;
    display:flex;align-items:center;justify-content:center;
}
.modal-close:hover{opacity:1;background:rgba(0,0,0,.05)}
.modal-title{font-family:var(--font-display);font-size:22px;color:var(--navy);text-align:center;margin-bottom:28px}

/* --------------------------------------------------------------------------
   Upload Cards
   -------------------------------------------------------------------------- */
.upload-guide-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:12px;margin-top:14px}
.upload-guide-card{
    display:flex;gap:14px;padding:16px 18px;
    background:#fff;border:1px solid var(--border);
    border-radius:var(--radius-lg);transition:all .25s var(--ease);
}
.upload-guide-card:hover{border-color:var(--navy);box-shadow:var(--shadow-md);transform:translateY(-1px)}
.upload-guide-drop{border-style:dashed;border-color:var(--border-dark)}
.guide-icon{font-size:28px;line-height:1;flex-shrink:0}
.guide-body h4{font-size:14px;font-weight:600;color:var(--ink);margin-bottom:4px}
.guide-body p{font-size:12px;color:var(--ink-light);line-height:1.6;margin-bottom:8px}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.footer{
    background:#3d1018;color:rgba(255,255,255,.45);
    padding:28px 0;text-align:center;font-size:12px;position:relative;z-index:1;
}
.footer a{color:rgba(255,255,255,.6);text-decoration:none;transition:color .2s}
.footer a:hover{color:var(--gold-light)}

/* --------------------------------------------------------------------------
   Report Card
   -------------------------------------------------------------------------- */
.report-section{margin-top:20px;display:none}
.report-section.visible{display:block;animation:fadeSlideIn .4s var(--ease)}
.report-content{
    font-family:var(--font-mono);font-size:13px;line-height:1.8;
    padding:20px 24px;background:#fdfdfc;border-radius:var(--radius-lg);
    border:1px solid var(--border);white-space:pre-wrap;
    border-left:4px solid var(--navy);
}

/* --------------------------------------------------------------------------
   Plan Cards
   -------------------------------------------------------------------------- */
.plan-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(120px,1fr));gap:10px;margin-bottom:24px}
.plan-card{
    text-align:center;padding:20px 14px;border:1.5px solid var(--border);
    border-radius:var(--radius-lg);cursor:pointer;background:#fff;
    transition:all .25s var(--ease);
}
.plan-card:hover{border-color:var(--navy);transform:translateY(-2px)}
.plan-card.selected{border-color:var(--navy);background:rgba(26,51,80,.04);box-shadow:var(--shadow-glow)}
.plan-price{font-family:var(--font-display);font-size:22px;color:var(--navy);margin-bottom:6px}
.plan-desc{font-size:12px;color:var(--ink-light)}

/* --------------------------------------------------------------------------
   Responsive
   -------------------------------------------------------------------------- */
@media(max-width:768px){
    .container{padding:0 16px}
    .header{padding:40px 0 48px}
    .header h1{font-size:28px}
    .tab-bar{overflow-x:auto;flex-wrap:nowrap}
    .tab-btn{padding:8px 16px;font-size:13px}
    .btn-row{flex-direction:column}
    .btn{width:100%;justify-content:center}
    .upload-guide-grid{grid-template-columns:1fr}
    .plan-grid{grid-template-columns:1fr 1fr}
}

/* ============================================================================
   V4 Interaction Layer — Micro-interactions & Polish
   ============================================================================ */

/* ── Focus Ring — branded outline ── */
input:focus-visible, textarea:focus-visible, select:focus-visible, button:focus-visible{
    outline:2px solid var(--navy);outline-offset:2px;border-radius:var(--radius-sm)
}
.btn:focus-visible{outline-offset:3px}

/* ── Textarea live character pulse ── */
.char-count{transition:color .25s var(--ease)}
.char-count.updating{color:var(--navy);font-weight:600}
.char-count .count-num{font-family:var(--font-mono);font-size:13px}

/* ── Tab content crossfade ── */
.tab-panel{animation:tabCrossfade .35s var(--ease)}
@keyframes tabCrossfade{
    from{opacity:0;filter:blur(4px);transform:translateY(6px)}
    to{opacity:1;filter:blur(0);transform:translateY(0)}
}

/* ── Button loading spinner ── */
.btn.is-loading{position:relative;color:transparent!important;pointer-events:none}
.btn.is-loading::before{
    content:'';position:absolute;inset:0;margin:auto;
    width:18px;height:18px;border:2px solid rgba(255,255,255,.3);
    border-top-color:#fff;border-radius:50%;
    animation:btnSpin .6s linear infinite
}
.btn-secondary.is-loading::before{border-color:rgba(26,51,80,.2);border-top-color:var(--navy)}
@keyframes btnSpin{to{transform:rotate(360deg)}}

/* ── Plan card radio pulse on select ── */
.plan-card.selected{animation:planSelect .4s var(--ease-spring)}
@keyframes planSelect{
    0%{transform:scale(1)}
    40%{transform:scale(1.03)}
    100%{transform:scale(1)}
}

/* ── File drop zone breathe ── */
.file-drop-zone{animation:dropBreathe 4s ease-in-out infinite}
@keyframes dropBreathe{
    0%,100%{border-color:var(--border-dark)}
    50%{border-color:rgba(26,51,80,.15)}
}
.file-drop-zone.drag-over{animation:none}

/* ── Report card slide reveal ── */
.report-section.visible{animation:reportReveal .45s var(--ease)}
@keyframes reportReveal{
    from{opacity:0;max-height:0;transform:translateY(-10px)}
    to{opacity:1;max-height:2000px;transform:translateY(0)}
}

/* ── Copy success flash ── */
.copied-flash{animation:copiedPop .5s var(--ease-spring)}
@keyframes copiedPop{
    0%{transform:scale(1)}
    50%{transform:scale(1.15);color:var(--success)}
    100%{transform:scale(1)}
}

/* ── Hover lift — cards ── */
.demo-card, .upload-guide-card, .plan-card, .pdf-card{
    transition:all .3s var(--ease),box-shadow .3s var(--ease),transform .3s var(--ease-spring)
}

/* ── Section divider breathing dot ── */
.demo-category-label::before{
    content:'';display:inline-block;width:6px;height:6px;border-radius:50%;
    background:var(--navy);margin-right:6px;vertical-align:middle;
    animation:dotPulse 2.5s ease-in-out infinite
}
@keyframes dotPulse{0%,100%{opacity:.4}50%{opacity:1}}

/* ── Quota bar shimmer on update ── */
.quota-bar.updated{animation:quotaFlash .6s var(--ease)}
@keyframes quotaFlash{
    0%,100%{background:var(--glass-bg)}
    50%{background:rgba(45,106,79,.08)}
}

/* ── Staggered card entrance ── */
.demo-card:nth-child(1){animation:cardIn .4s .05s var(--ease) both}
.demo-card:nth-child(2){animation:cardIn .4s .1s var(--ease) both}
.demo-card:nth-child(3){animation:cardIn .4s .15s var(--ease) both}
.demo-card:nth-child(4){animation:cardIn .4s .2s var(--ease) both}
.demo-card:nth-child(5){animation:cardIn .4s .25s var(--ease) both}
@keyframes cardIn{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:translateY(0)}}

/* --------------------------------------------------------------------------
   Extension Promo Card — Tab IV
   -------------------------------------------------------------------------- */
.extension-promo{
    border:1.5px solid var(--gold);background:linear-gradient(135deg,rgba(155,125,60,.06),rgba(107,29,42,.03));
    border-radius:var(--radius-lg);padding:20px 22px;margin-bottom:20px;
    position:relative;overflow:hidden;
}
.extension-promo::before{
    content:'';position:absolute;top:0;left:0;width:4px;height:100%;
    background:linear-gradient(180deg,var(--navy),var(--gold));
}
.extension-promo-title{
    font-family:var(--font-display);font-size:15px;font-weight:600;
    color:var(--navy);margin-bottom:6px;letter-spacing:.3px;
}
.extension-promo-desc{
    margin:0 0 12px;font-size:13px;color:var(--ink-light);line-height:1.7;
}
.extension-promo-btn{
    display:inline-flex;align-items:center;gap:6px;
    padding:10px 24px;background:var(--navy);color:#fff;
    border-radius:var(--radius);text-decoration:none;font-size:13px;font-weight:600;
    transition:all .25s var(--ease);
}
.extension-promo-btn:hover{background:var(--navy-light);transform:translateY(-1px);box-shadow:var(--shadow-md)}
.extension-promo-hint{
    margin-top:10px;font-size:12px;color:var(--ink-light);line-height:1.8;
}
.extension-promo-hint code{
    background:rgba(26,20,16,.06);padding:1px 6px;border-radius:3px;
    font-family:var(--font-mono);font-size:11px;
}

/* ── Mobile tap highlight removal ── */
*{-webkit-tap-highlight-color:transparent}

/* ============================================================================
   V5 Text Micro-Interactions — hover 微放大
   ============================================================================ */

/* Inline interactive text gets scale on hover */
.btn, .btn span,
.tab-btn,
.demo-card-name, .demo-card-btn,
.upload-guide-card h4,
.input-label, .demo-section-title,
.preset-btn, .style-tab,
.pdf-card h4, .info-card h4,
.modal-title, .plan-label,
.quota-text, .quota-text span,
p a, .footer a,
.section-heading,
.guide-body h4,
.demo-category-label{
    transition: transform .25s var(--ease-spring), letter-spacing .25s var(--ease), color .2s var(--ease);
}

.btn:hover, .btn:hover span,
.tab-btn:hover,
.demo-card-name:hover,
.demo-card-btn:hover,
.upload-guide-card:hover h4,
.input-label:hover,
.demo-section-title:hover,
.preset-btn:hover, .style-tab:hover,
.modal-title:hover, .plan-label:hover,
p a:hover, .footer a:hover,
.section-heading:hover,
.pdf-card h4:hover, .info-card h4:hover,
.guide-body h4:hover,
.demo-category-label:hover{
    transform: scale(1.04);
    letter-spacing: .03em;
}

/* Buttons/tabs get bigger pop */
.btn:hover, .tab-btn:hover{
    transform: scale(1.05);
}

/* Headings — subtle lift without breaking layout */
.header h1:hover, .header .subtitle:hover{
    transform: scale(1.02);
    transition: transform .3s var(--ease-spring);
}

/* Plan cards — whole card text lifts */
.plan-card:hover .plan-price{transform:scale(1.06)}
.plan-card:hover .plan-label{transform:scale(1.03)}

/* Links turn gold */
p a, .footer a{transition:color .2s var(--ease),transform .25s var(--ease-spring)}
p a:hover, .footer a:hover{color:var(--gold)}

/* ==========================================================================
   使用教程 Guide Section — 与 info-card / demo-card 风格统一
   ========================================================================== */
.guide-section {
    margin-bottom: 16px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    background: var(--paper);
}
.guide-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 16px;
    background: var(--paper);
    cursor: pointer;
    user-select: none;
    transition: background .2s;
    border-bottom: 1px solid transparent;
}
.guide-header:hover { background: #fafbfc; }
.guide-body:not(.collapsed) + .guide-header,
.guide-section:has(.guide-body:not(.collapsed)) .guide-header { border-bottom-color: var(--border); }
.guide-title {
    font-family: var(--font-display);
    font-size: 15px;
    font-weight: 600;
    color: var(--navy);
    letter-spacing: .3px;
}
.guide-toggle {
    font-size: 11px;
    color: var(--ink-light);
    transition: transform .3s var(--ease);
}
.guide-body {
    transition: max-height .35s var(--ease), opacity .25s var(--ease);
    max-height: 2000px;
    overflow: hidden;
}
.guide-body.collapsed { max-height: 0; opacity: 0; }
.guide-steps {
    padding: 0 16px 16px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 12px;
}
.guide-step {
    display: flex;
    gap: 10px;
    align-items: flex-start;
    padding: 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: #fafbfc;
    transition: border-color .2s, box-shadow .2s;
}
.guide-step:hover {
    border-color: var(--gold-light);
    box-shadow: 0 2px 12px rgba(184,134,11,.08);
}
.guide-step-num {
    flex-shrink: 0;
    width: 28px; height: 28px;
    border-radius: 50%;
    background: var(--gold);
    color: #fff;
    font-weight: 700;
    font-size: 13px;
    display: flex; align-items: center; justify-content: center;
    line-height: 1;
}
.guide-step-content { min-width: 0; }
.guide-step-content h4 {
    margin: 0 0 3px 0;
    font-size: 13px;
    font-weight: 600;
    color: var(--navy);
    display: flex; align-items: center; gap: 6px;
    flex-wrap: wrap;
}
.guide-step-content p {
    margin: 0;
    font-size: 12px;
    color: var(--ink-light);
    line-height: 1.65;
}
.guide-tab-tag {
    font-size: 10px;
    font-weight: 600;
    background: rgba(184,134,11,.12);
    color: var(--gold-dark, #8b6914);
    padding: 1px 7px;
    border-radius: 9px;
    white-space: nowrap;
    letter-spacing: .2px;
}
.guide-step-content code {
    background: rgba(0,0,0,.04);
    padding: 1px 5px;
    border-radius: 3px;
    font-size: 11px;
    font-family: var(--font-mono, 'JetBrains Mono', 'Consolas', monospace);
    color: var(--ink);
}
.guide-step-content a { color: var(--gold-dark, #8b6914); text-decoration: underline; }
.guide-step-content a:hover { color: var(--gold); }

/* ═══════════════════════════════════════════
   统一上传区
   ═══════════════════════════════════════════ */
.unified-upload-zone {
    border: 2px dashed var(--border);
    border-radius: 12px;
    padding: 36px 24px;
    text-align: center;
    cursor: pointer;
    transition: all .2s;
    background: var(--paper);
    margin: 12px 0 0;
}
.unified-upload-zone:hover,
.unified-upload-zone.drag-over {
    border-color: var(--gold);
    background: rgba(184,134,11,0.04);
}
.unified-upload-icon { font-size: 36px; margin-bottom: 8px; }
.unified-upload-title { font-size: 16px; font-weight: 600; color: var(--navy); margin-bottom: 4px; }
.unified-upload-hint { font-size: 12px; color: var(--ink-light); margin-bottom: 16px; }
.unified-upload-btns { display: flex; gap: 10px; justify-content: center; }