:root {
    --bg: #0a0e17;
    --bg-2: #0d1220;
    --panel: rgba(18, 24, 38, 0.72);
    --border: rgba(0, 240, 255, 0.16);
    --border-strong: rgba(0, 240, 255, 0.45);
    --cyan: #00f0ff;
    --cyan-deep: #00b8c4;
    --text: #e6edf6;
    --text-dim: #8a99ad;
    --text-mute: #5b6678;
    --danger: #ff5a6a;
    --success: #2dd4a7;
    --radius: 16px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
    font-family: 'Noto Sans SC', -apple-system, sans-serif;
    background: radial-gradient(1200px 800px at 80% -10%, #11203a 0%, var(--bg) 55%);
    color: var(--text);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    overflow-x: hidden;
    position: relative;
}

#bg-particles { position: fixed; inset: 0; z-index: 0; }

/* ===== 布局 ===== */
.auth-wrapper {
    position: relative;
    z-index: 1;
    width: min(1040px, 94vw);
    margin: 40px auto;
    display: grid;
    grid-template-columns: 1.05fr 0.95fr;
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: 24px;
    overflow: hidden;
    backdrop-filter: blur(18px);
    box-shadow: 0 30px 80px rgba(0, 0, 0, 0.5);
}

/* ===== 品牌面板 ===== */
.brand-panel {
    position: relative;
    padding: 48px 44px;
    background:
        linear-gradient(160deg, rgba(0, 240, 255, 0.08), transparent 60%),
        linear-gradient(0deg, rgba(10, 14, 23, 0.6), rgba(13, 18, 32, 0.3));
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
}
.brand-logo { display: flex; align-items: center; gap: 12px; text-decoration: none; color: var(--text); }
.logo-hex { font-size: 32px; color: var(--cyan); filter: drop-shadow(0 0 12px rgba(0, 240, 255, 0.6)); }
.logo-name { font-family: 'Orbitron', sans-serif; font-weight: 700; font-size: 24px; letter-spacing: 1px; }
.logo-name small { font-family: 'Noto Sans SC'; font-weight: 400; font-size: 13px; color: var(--text-dim); margin-left: 6px; letter-spacing: 0; }

.brand-copy { margin-top: auto; margin-bottom: auto; }
.brand-copy h1 { font-size: 34px; line-height: 1.3; font-weight: 900; margin-bottom: 18px; }
.brand-copy > p { color: var(--text-dim); line-height: 1.8; font-size: 14px; margin-bottom: 28px; max-width: 360px; }
.brand-points { list-style: none; display: flex; flex-direction: column; gap: 14px; }
.brand-points li { display: flex; align-items: center; gap: 10px; font-size: 14px; color: var(--text); }
.bp-icon { color: var(--cyan); font-size: 12px; }
.brand-foot { margin-top: 32px; font-size: 12px; color: var(--text-mute); letter-spacing: 0.5px; }

/* ===== 认证卡片 ===== */
.auth-card { position: relative; padding: 40px 44px 28px; display: flex; flex-direction: column; }

.auth-tabs { position: relative; display: flex; gap: 8px; background: rgba(0,0,0,0.25); border: 1px solid var(--border); border-radius: 12px; padding: 5px; width: fit-content; margin: 0 auto 4px; }
.auth-tab { position: relative; z-index: 1; border: none; background: transparent; color: var(--text-dim); font-family: inherit; font-size: 15px; font-weight: 500; padding: 9px 30px; border-radius: 9px; cursor: pointer; transition: color .25s; }
.auth-tab.active { color: var(--bg); }
.tab-indicator { position: absolute; top: 5px; left: 5px; height: calc(100% - 10px); width: calc(50% - 5px); background: linear-gradient(135deg, var(--cyan-deep), var(--cyan)); border-radius: 9px; transition: transform .28s cubic-bezier(.4,0,.2,1); z-index: 0; }
.auth-tabs[data-mode="register"] .tab-indicator { transform: translateX(100%); }

.auth-body { margin-top: 22px; }
.auth-title { font-size: 24px; font-weight: 700; }
.auth-sub { color: var(--text-dim); font-size: 13px; margin-top: 6px; margin-bottom: 24px; }

.field { margin-bottom: 18px; }
.field label { display: block; font-size: 13px; color: var(--text-dim); margin-bottom: 8px; }
.input-wrap { position: relative; display: flex; align-items: center; background: rgba(0,0,0,0.28); border: 1px solid var(--border); border-radius: 11px; transition: border-color .2s, box-shadow .2s; }
.input-wrap:focus-within { border-color: var(--border-strong); box-shadow: 0 0 0 3px rgba(0,240,255,0.08); }
.input-icon { width: 44px; text-align: center; color: var(--text-mute); font-size: 15px; flex-shrink: 0; }
.input-wrap input { flex: 1; background: transparent; border: none; outline: none; color: var(--text); font-family: inherit; font-size: 15px; padding: 14px 14px 14px 0; }
.input-wrap input::placeholder { color: var(--text-mute); }

.send-code-btn { flex-shrink: 0; margin-right: 6px; padding: 8px 14px; background: rgba(0,240,255,0.1); border: 1px solid var(--border-strong); color: var(--cyan); border-radius: 8px; font-family: inherit; font-size: 13px; cursor: pointer; white-space: nowrap; transition: all .2s; }
.send-code-btn:hover:not(:disabled) { background: rgba(0,240,255,0.18); }
.send-code-btn:disabled { color: var(--text-mute); border-color: var(--border); cursor: not-allowed; background: transparent; }

.form-hint { min-height: 18px; font-size: 12.5px; margin: -6px 0 14px; }
.form-hint.error { color: var(--danger); }
.form-hint.success { color: var(--success); }
.form-hint.info { color: var(--text-dim); }

.submit-btn { position: relative; width: 100%; padding: 14px; border: none; border-radius: 11px; background: linear-gradient(135deg, var(--cyan-deep), var(--cyan)); color: var(--bg); font-family: inherit; font-size: 16px; font-weight: 700; cursor: pointer; transition: transform .15s, box-shadow .2s; overflow: hidden; }
.submit-btn:hover { box-shadow: 0 8px 26px rgba(0,240,255,0.32); transform: translateY(-1px); }
.submit-btn:active { transform: translateY(0); }
.submit-btn:disabled { opacity: .65; cursor: not-allowed; }
.btn-spinner { display: none; width: 18px; height: 18px; border: 2px solid rgba(10,14,23,0.35); border-top-color: var(--bg); border-radius: 50%; animation: spin .7s linear infinite; vertical-align: middle; margin-left: 8px; }
.submit-btn.loading .btn-spinner { display: inline-block; }
.submit-btn.loading .btn-text { opacity: .8; }
@keyframes spin { to { transform: rotate(360deg); } }

.auth-switch { text-align: center; margin-top: 20px; font-size: 14px; color: var(--text-dim); }
.auth-switch a { color: var(--cyan); text-decoration: none; font-weight: 500; }
.auth-switch a:hover { text-decoration: underline; }
.auth-agreement { text-align: center; margin-top: 14px; font-size: 12px; color: var(--text-mute); }
.auth-agreement a { color: var(--text-dim); text-decoration: none; }
.auth-agreement a:hover { color: var(--cyan); }

.back-home { margin-top: auto; padding-top: 22px; text-align: center; font-size: 13px; color: var(--text-mute); text-decoration: none; transition: color .2s; }
.back-home:hover { color: var(--cyan); }

/* ===== Toast ===== */
.toast { position: fixed; top: 28px; left: 50%; transform: translateX(-50%) translateY(-20px); background: rgba(18,24,38,0.96); border: 1px solid var(--border-strong); color: var(--text); padding: 13px 22px; border-radius: 10px; font-size: 14px; z-index: 999; opacity: 0; pointer-events: none; transition: all .3s; backdrop-filter: blur(10px); box-shadow: 0 10px 30px rgba(0,0,0,.4); }
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }
.toast.error { border-color: var(--danger); }
.toast.success { border-color: var(--success); }

/* ===== 滑块人机验证 ===== */
.cap-mask { position: fixed; inset: 0; z-index: 1000; background: rgba(4,7,12,.6); backdrop-filter: blur(4px); display: flex; align-items: center; justify-content: center; animation: capfade .2s ease; }
@keyframes capfade { from { opacity: 0; } to { opacity: 1; } }
.cap-panel { width: 340px; max-width: 92vw; background: #11182a; border: 1px solid var(--border-strong); border-radius: 16px; padding: 18px; box-shadow: 0 30px 70px rgba(0,0,0,.6); }
.cap-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 14px; font-size: 15px; font-weight: 600; }
.cap-actions { display: flex; gap: 6px; }
.cap-refresh, .cap-close { width: 30px; height: 30px; border-radius: 8px; border: 1px solid var(--border); background: rgba(255,255,255,.04); color: var(--text-dim); cursor: pointer; font-size: 16px; line-height: 1; }
.cap-refresh:hover, .cap-close:hover { color: var(--cyan); border-color: var(--border-strong); }
.cap-stage { position: relative; width: 300px; max-width: 100%; height: 180px; border-radius: 10px; overflow: hidden; margin: 0 auto; background: #0a0e17; }
.cap-bg { position: absolute; inset: 0; width: 300px; height: 180px; user-select: none; }
.cap-piece { position: absolute; top: 0; left: 0; width: 44px; height: 44px; filter: drop-shadow(0 2px 6px rgba(0,0,0,.5)); user-select: none; }
.cap-tip { position: absolute; left: 0; bottom: 0; width: 100%; padding: 5px 0; text-align: center; font-size: 12px; color: #fff; background: linear-gradient(0deg, rgba(0,0,0,.55), transparent); }
.cap-track { position: relative; height: 42px; margin-top: 16px; background: rgba(0,0,0,.3); border: 1px solid var(--border); border-radius: 21px; user-select: none; overflow: hidden; }
.cap-fill { position: absolute; left: 0; top: 0; height: 100%; width: 0; background: linear-gradient(90deg, rgba(0,240,255,.18), rgba(0,240,255,.35)); }
.cap-track-text { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; font-size: 13px; color: var(--text-mute); pointer-events: none; transition: opacity .2s; }
.cap-handle { position: absolute; top: 0; left: 0; width: 42px; height: 42px; margin: -1px; border-radius: 21px; background: linear-gradient(135deg, var(--cyan-deep), var(--cyan)); color: var(--bg); display: flex; align-items: center; justify-content: center; font-size: 20px; font-weight: 700; cursor: grab; box-shadow: 0 2px 10px rgba(0,240,255,.4); z-index: 2; }
.cap-handle.grab { cursor: grabbing; }
.cap-track.cap-ok .cap-fill { background: linear-gradient(90deg, rgba(45,212,167,.3), rgba(45,212,167,.5)); }
.cap-track.cap-ok .cap-handle { background: linear-gradient(135deg, #1fae89, var(--success)); }
.cap-track.cap-ok .cap-track-text { color: var(--success); }
.cap-track.cap-err .cap-fill { background: linear-gradient(90deg, rgba(255,90,106,.3), rgba(255,90,106,.5)); }
.cap-track.cap-err .cap-handle { background: linear-gradient(135deg, #d63b4a, var(--danger)); animation: capshake .3s; }
.cap-track.cap-err .cap-track-text { color: var(--danger); }
@keyframes capshake { 0%,100%{transform:translateX(0)} 25%{transform:translateX(-4px)} 75%{transform:translateX(4px)} }

/* ===== 响应式 ===== */
@media (max-width: 860px) {
    .auth-wrapper { grid-template-columns: 1fr; width: 94vw; }
    .brand-panel { display: none; }
    .auth-card { padding: 32px 26px 22px; }
}