/* 符豆：轻盈、清晰的玻璃界面 */
:root{--ink:#202d38;--muted:#697986;--accent:#336e82;--line:rgba(255,255,255,.82);--glass:rgba(255,255,255,.68);--shadow:0 18px 50px rgba(54,84,99,.09)}
html{scroll-behavior:smooth}body{font-family:-apple-system,BlinkMacSystemFont,"SF Pro Display","PingFang SC","Microsoft YaHei",sans-serif;color:var(--ink);background:radial-gradient(ellipse at 10% 5%,#d7e8ee 0,transparent 35%),radial-gradient(ellipse at 93% 15%,#e8ebe2 0,transparent 36%),#f4f7f7;line-height:1.6;min-height:100vh}.container{max-width:1280px}.main-content{min-height:calc(100vh - 210px)}a{color:#326e80}a:hover{color:#214f5e}
.glass-nav{position:sticky;top:0;z-index:1030;background:rgba(247,250,250,.76);backdrop-filter:blur(22px) saturate(145%);-webkit-backdrop-filter:blur(22px) saturate(145%);border-bottom:1px solid rgba(255,255,255,.8);box-shadow:0 3px 24px rgba(39,67,79,.045);padding:.65rem 0}.glass-nav .navbar-brand{font-weight:700;color:#253a46;font-size:1rem;letter-spacing:.01em;white-space:nowrap}.glass-nav .navbar-brand i{display:inline-flex;align-items:center;justify-content:center;width:35px;height:35px;margin-right:8px;border-radius:12px;background:linear-gradient(145deg,#709dad,#41778a);color:#fff;font-size:.9rem;box-shadow:0 5px 12px #739a9e55}.glass-nav .nav-link{color:#526672!important;font-size:.88rem;font-weight:500;border-radius:12px;padding:.55rem .68rem!important}.glass-nav .nav-link:hover,.glass-nav .nav-link:focus{color:#234e5d!important;background:rgba(255,255,255,.7)}.glass-nav .navbar-toggler{border:1px solid #cddbdc;border-radius:10px}.glass-nav .dropdown-menu{border:1px solid #fff;border-radius:15px;background:rgba(249,252,252,.95);box-shadow:var(--shadow);padding:7px}.glass-nav .dropdown-item{border-radius:9px;padding:.55rem .8rem}
.card,.practice-card{background:var(--glass);border:1px solid var(--line);border-radius:22px;box-shadow:var(--shadow),inset 0 1px rgba(255,255,255,.85);backdrop-filter:blur(18px);-webkit-backdrop-filter:blur(18px);padding:0;overflow:hidden;color:var(--ink);transition:box-shadow .2s ease,transform .2s ease}.card:hover,.practice-card:hover{transform:translateY(-2px);box-shadow:0 22px 50px rgba(54,84,99,.13)}.card-body{padding:1.45rem}.card-header{background:rgba(255,255,255,.42);border:0;border-bottom:1px solid rgba(120,151,157,.16);padding:1.1rem 1.45rem;margin:0;color:var(--ink)}.card-header.bg-primary{background:linear-gradient(125deg,#628e9a,#436e80)!important;color:#fff}.card-footer{background:rgba(244,249,249,.55);border-color:rgba(120,151,157,.16);padding:1rem}.card-title{color:var(--ink);font-size:1.15rem;font-weight:650}.practice-card{padding:1.5rem}.practice-card h3{font-size:1.15rem;color:var(--ink)}.practice-card p{color:var(--muted)}
h1,h2,h3,h4,h5,h6{letter-spacing:-.025em;color:var(--ink)}.text-primary{color:#3c788c!important}.text-muted{color:#71818b!important}.btn{border-radius:999px;padding:.7rem 1.2rem;font-size:.92rem;font-weight:600;line-height:1.35;transition:transform .18s ease,box-shadow .18s ease,background .18s ease}.btn:hover{transform:translateY(-1px)}.btn:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,button:focus-visible{outline:3px solid #70aabc;outline-offset:3px}.btn-primary,.btn-success{background:#326f82;border:1px solid #326f82;color:#fff;box-shadow:0 7px 16px #386f8128}.btn-primary:hover,.btn-success:hover{background:#285f70;border-color:#285f70;color:white}.btn-outline-primary,.btn-outline-success,.btn-outline-secondary{background:rgba(255,255,255,.55);border:1px solid #c9dadd;color:#315f6e}.btn-outline-primary:hover,.btn-outline-success:hover,.btn-outline-secondary:hover{background:#e5f0f1;border-color:#aecbd0;color:#234b58}.btn-sm{padding:.4rem .8rem;font-size:.82rem}.btn:disabled{transform:none;box-shadow:none}.form-control,.form-select,.input-group-text{border:1px solid #d5e1e2;border-radius:12px;background:rgba(255,255,255,.75);color:var(--ink);font-size:.95rem}.form-control:focus,.form-select:focus{border-color:#78aab7;box-shadow:0 0 0 .2rem #8db8c340;background:#fff}.form-label{font-weight:600;font-size:.9rem;color:#4b606b}.input-group-text{border-radius:12px}.table{--bs-table-bg:transparent;--bs-table-color:var(--ink);--bs-table-border-color:rgba(104,139,149,.15);vertical-align:middle}.table th{font-size:.82rem;color:var(--muted);font-weight:600}.table td,.table th{padding:.85rem}.badge{border-radius:999px;padding:.45em .7em}.alert{border-radius:15px}.progress{background:#e3eceb;border-radius:99px}.progress-bar{background:#5f9b9e}.site-footer{border-top:1px solid #dce7e6;margin-top:60px;padding:28px 0 35px;color:#7c8c91;font-size:.85rem}.footer-inner{display:flex;justify-content:space-between;align-items:center;gap:20px}.footer-inner strong{color:#496570}.footer-inner p{margin:4px 0 0}
.home-page{padding-top:28px}.home-hero{position:relative;min-height:510px;display:grid;grid-template-columns:1.08fr .92fr;align-items:center;overflow:hidden;border-radius:32px;background:linear-gradient(120deg,rgba(255,255,255,.82),rgba(235,245,245,.58));border:1px solid #fff;box-shadow:0 25px 70px rgba(55,92,99,.10),inset 0 1px #fff}.hero-copy{z-index:2;padding:65px 0 62px 7.4%}.eyebrow{display:inline-flex;align-items:center;gap:9px;font-size:.72rem;letter-spacing:.15em;font-weight:700;color:#648590}.eyebrow-dot{width:7px;height:7px;background:#73a89f;border-radius:50%}.home-hero h1{font-size:clamp(2.5rem,4.6vw,4.2rem);font-weight:720;line-height:1.22;letter-spacing:-.055em;margin:25px 0;color:#253b46}.home-hero h1 span{color:#668f98}.hero-copy>p{max-width:440px;font-size:1rem;line-height:1.9;color:#697e85}.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:30px}.hero-actions .btn{padding:.85rem 1.45rem}.hero-actions .btn span,.home-cta .btn span{margin-left:12px}.hero-caption{display:flex;align-items:center;gap:12px;color:#91a4a7;font-size:.78rem;margin-top:57px}.hero-caption span{width:35px;height:1px;background:#a5bfbd}.hero-art{position:relative;min-height:510px;align-self:stretch;background:radial-gradient(circle at 51% 47%,rgba(205,229,226,.8),transparent 56%)}.art-disc{position:absolute;width:310px;height:310px;top:50%;left:52%;transform:translate(-50%,-50%);border-radius:50%;background:linear-gradient(145deg,rgba(255,255,255,.82),rgba(201,226,229,.38));border:1px solid #fff;box-shadow:inset 0 0 0 25px rgba(255,255,255,.18),inset 0 0 0 26px rgba(255,255,255,.5),0 25px 55px #699ba22f;display:grid;place-items:center;backdrop-filter:blur(15px)}.disc-core{width:120px;height:120px;border:1px solid #ffffffbf;border-radius:50%;display:grid;place-items:center;color:#5e909b;background:linear-gradient(145deg,#ffffffba,#bedbdc88);font-size:2.4rem;box-shadow:inset 0 1px 6px #fff,0 10px 20px #6696952b}.art-orbit{position:absolute;border:1px solid rgba(135,174,177,.23);border-radius:50%;top:50%;left:52%;transform:translate(-50%,-50%)}.orbit-one{width:390px;height:390px}.orbit-two{width:455px;height:455px}.art-tag{position:absolute;bottom:71px;left:6%;display:flex;align-items:center;gap:12px;padding:13px 18px;background:#ffffffc7;border:1px solid white;border-radius:18px;box-shadow:0 16px 35px #5c8b9125;backdrop-filter:blur(16px)}.art-tag-icon{display:grid;place-items:center;width:38px;height:38px;border-radius:13px;background:#e4f1ef;color:#64968e}.art-tag b,.art-tag small{display:block}.art-tag b{font-size:.85rem}.art-tag small{font-size:.72rem;color:#8a9b9e}.art-note{position:absolute;color:#8bb8b8;font-size:2rem}.note-one{top:17%;right:20%}.note-two{right:11%;bottom:23%;font-size:1.4rem;color:#abc5ba}.home-features{padding:100px 0 80px}.section-heading{display:flex;justify-content:space-between;align-items:end;gap:25px;margin-bottom:32px}.section-heading h2,.home-cta h2{font-size:clamp(1.65rem,3vw,2.3rem);line-height:1.35;font-weight:700;margin:14px 0 0}.section-heading p,.home-cta p{color:#7a8d91;margin:0;line-height:1.8}.feature-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.feature-tile{min-height:225px;padding:27px;border-radius:23px;background:rgba(255,255,255,.62);border:1px solid #fff;box-shadow:0 12px 32px #5b7b810b}.feature-symbol{display:grid;place-items:center;width:47px;height:47px;border-radius:16px;font-size:1rem}.tone-blue{background:#e1eff3;color:#658f9e}.tone-mint{background:#e2f1eb;color:#73a58e}.tone-peach{background:#f7ece3;color:#be9481}.feature-tile h3{font-size:1.1rem;font-weight:650;margin:21px 0 8px}.feature-tile p{font-size:.9rem;color:#7a8d91;margin:0 0 24px}.tile-label{font-size:.62rem;letter-spacing:.13em;color:#a0b0b2;font-weight:700}.home-cta{display:flex;align-items:center;justify-content:space-between;gap:30px;padding:34px 40px;border-radius:25px;background:linear-gradient(100deg,#e4f0ef,#edf3ee);border:1px solid #fff}.home-cta h2{font-size:1.5rem;margin:8px 0}.home-cta p{font-size:.9rem}
.singing-page .singing-card{background:var(--glass);border:1px solid white;border-radius:22px;box-shadow:var(--shadow);backdrop-filter:blur(18px)}.singing-page .score-preview,.singing-page .singing-status{background:rgba(239,246,245,.8)}
@media(max-width:991px){.glass-nav .navbar-collapse{padding:12px 0}.glass-nav .navbar-nav{gap:3px}.glass-nav .nav-link{padding:.7rem!important}.home-hero{grid-template-columns:1fr 1fr}.hero-copy{padding-left:7%}.art-disc{width:250px;height:250px}.orbit-one{width:310px;height:310px}.orbit-two{width:360px;height:360px}}
@media(max-width:767px){.container{padding-left:20px;padding-right:20px}.home-page{padding-top:14px}.home-hero{display:flex;flex-direction:column;min-height:0}.hero-copy{padding:42px 26px 0}.home-hero h1{font-size:2.55rem;margin:20px 0}.hero-caption{margin-top:30px}.hero-art{min-height:300px;width:100%}.art-disc{width:210px;height:210px}.disc-core{width:88px;height:88px;font-size:1.7rem}.orbit-one{width:260px;height:260px}.orbit-two{width:300px;height:300px}.art-tag{left:7%;bottom:20px}.art-note.note-one{top:11%}.home-features{padding:65px 0 48px}.section-heading{display:block}.section-heading p{margin-top:14px}.feature-grid{grid-template-columns:1fr}.feature-tile{min-height:0}.home-cta{padding:28px;align-items:flex-start;flex-direction:column}.footer-inner{align-items:flex-start;flex-direction:column}.card{margin-bottom:1rem}.row>[class*='col-md-']{max-width:100%;flex-basis:auto}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto!important;transition-duration:.01ms!important;animation-duration:.01ms!important;animation-iteration-count:1!important}}
.card-header.bg-primary h1,.card-header.bg-primary h2,.card-header.bg-primary h3,.card-header.bg-primary h4,.card-header.bg-primary h5{color:#fff}

/* 首页音乐装饰：缓慢的呼吸、环绕与漂浮 */
@media (prefers-reduced-motion: no-preference) {
  .hero-art .art-disc { animation: disc-breathe 7s ease-in-out infinite; }
  .hero-art .disc-core { animation: core-glow 7s ease-in-out infinite; }
  .hero-art .disc-core i { animation: note-breathe 7s ease-in-out infinite; }
  .hero-art .art-orbit::after {
    content: ''; position: absolute; top: -4px; left: calc(50% - 4px);
    width: 8px; height: 8px; border-radius: 50%;
    background: rgba(115, 172, 174, .65); box-shadow: 0 0 12px rgba(115, 172, 174, .5);
  }
  .hero-art .orbit-one { animation: orbit-clockwise 30s linear infinite; }
  .hero-art .orbit-two { animation: orbit-counter 42s linear infinite; }
  .hero-art .orbit-two::after { width: 5px; height: 5px; top: -3px; background: rgba(163, 190, 174, .7); }
  .hero-art .note-one { animation: note-float 5.5s ease-in-out infinite; }
  .hero-art .note-two { animation: note-float 6.5s ease-in-out -2s infinite; }
  .hero-art .art-tag { animation: tag-float 8s ease-in-out infinite; }
}
@keyframes disc-breathe {
  0%,100% { transform: translate(-50%,-50%) scale(1); }
  50% { transform: translate(-50%,-50%) scale(1.025); }
}
@keyframes core-glow {
  0%,100% { box-shadow: inset 0 1px 6px #fff,0 10px 20px #6696952b; }
  50% { box-shadow: inset 0 1px 9px #fff,0 12px 32px #66969555; }
}
@keyframes note-breathe {
  0%,100% { transform: scale(1); opacity: .85; }
  50% { transform: scale(1.07); opacity: 1; }
}
@keyframes orbit-clockwise { from { transform: translate(-50%,-50%) rotate(0deg); } to { transform: translate(-50%,-50%) rotate(360deg); } }
@keyframes orbit-counter { from { transform: translate(-50%,-50%) rotate(0deg); } to { transform: translate(-50%,-50%) rotate(-360deg); } }
@keyframes note-float {
  0%,100% { transform: translateY(0) rotate(-4deg); opacity: .65; }
  50% { transform: translateY(-12px) rotate(6deg); opacity: 1; }
}
@keyframes tag-float { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-5px); } }
.lesson-row{display:flex;align-items:center;gap:16px;padding:16px 4px;color:var(--ink);border-bottom:1px solid rgba(104,139,149,.15)}.lesson-row:last-child{border-bottom:0}.lesson-row:hover{color:var(--accent)}.lesson-number{display:grid;place-items:center;flex:none;width:42px;height:42px;border-radius:14px;color:#4b8290;background:#e8f3f2;font-weight:700}.lesson-info{flex:1;min-width:0}.lesson-info strong,.lesson-info small{display:block}.lesson-info small{color:var(--muted);margin-top:3px}.lesson-arrow{font-size:1.25rem;color:#7ba4aa}.lesson-content{white-space:pre-wrap;line-height:1.9;color:#415661}.course-cover-placeholder{height:200px;display:grid;place-items:center;background:linear-gradient(140deg,#e0efef,#f1f5ee);color:#83aaab;font-size:3rem}