/* ---------- 设计令牌 ---------- */
:root {
    --bg-color: #f8f9fa;
    --bg-gradient-end: #f0f2f5;
    --text-color: #212529;
    --card-bg: #ffffff;
    --card-border: transparent;
    --primary: #4e54c8;
    --secondary: #8f94fb;
    --border-color: #e2e5ea;
    --muted-color: #6c757d;
    --input-bg: #f8f9fa;
    --input-border: #ced4da;
    --label-color: #212529;
    --footer-color: #6c757d;
    --danger: #dc2626;          /* WCAG AA 对比度达标 */
    --success: #16a34a;
    --shadow-card: 0 4px 24px rgba(20, 24, 50, 0.08);
    --ring-track: rgba(0, 0, 0, 0.08);
    /* 倒计时颜色，由 JS 动态修改 */
    --timer-hue: 230;
    --timer-color: hsl(var(--timer-hue) 70% 55%);
}

body.dark-mode {
    --bg-color: #0f1014;
    --bg-gradient-end: #15161c;
    --text-color: #f1f3f5;
    --card-bg: #1f2128;          /* 比之前的 #1e1e1e 提亮，分层更清楚 */
    --card-border: rgba(255, 255, 255, 0.06);
    --primary: #818cf8;
    --secondary: #a5b4fc;
    --border-color: #2a2d36;
    --muted-color: #9aa0aa;
    --input-bg: #16181e;
    --input-border: #353945;
    --label-color: #e9ecef;
    --footer-color: #9aa0aa;
    --danger: #f87171;
    --success: #4ade80;
    --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.4);
    --ring-track: rgba(255, 255, 255, 0.08);
    --timer-color: hsl(var(--timer-hue) 80% 70%);
}

/* ---------- 基础 ---------- */
* { box-sizing: border-box; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: linear-gradient(135deg, var(--bg-color) 0%, var(--bg-gradient-end) 100%);
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    margin: 0;
    transition: background 0.3s ease, color 0.3s ease;
    -webkit-font-smoothing: antialiased;
}

button {
    font-family: inherit;
    font-size: inherit;
}

.icon {
    width: 1em;
    height: 1em;
    display: inline-block;
    vertical-align: -0.15em;
    fill: currentColor;
}

.container {
    max-width: 480px;
    width: 100%;
    margin: 0 auto;
    padding: max(20px, env(safe-area-inset-top)) 20px env(safe-area-inset-bottom);
    flex: 1;
    display: flex;
    flex-direction: column;
}

/* ---------- 头部 ---------- */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 1px solid var(--border-color);
}

.header h2 {
    margin: 0;
    font-weight: 700;
    color: var(--primary);
    font-size: 1.5rem;
    display: flex;
    align-items: center;
    gap: 8px;
    letter-spacing: 0.02em;
}

.header h2 .icon {
    width: 1.2em;
    height: 1.2em;
}

.theme-switch {
    background: rgba(0, 0, 0, 0.05);
    border: none;
    color: var(--text-color);
    cursor: pointer;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    transition: background-color 0.2s ease, color 0.2s ease;
}

body.dark-mode .theme-switch {
    background-color: rgba(255, 255, 255, 0.08);
}

.theme-switch:hover {
    background-color: var(--primary);
    color: white;
}

/* ---------- 卡片 ---------- */
.card {
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 14px;
    padding: 22px;
    margin-bottom: 16px;
    box-shadow: var(--shadow-card);
    transition: background-color 0.3s ease, transform 0.15s ease, box-shadow 0.2s ease;
}

/* ---------- 输入区 ---------- */
.form-label {
    display: block;
    color: var(--label-color);
    font-weight: 500;
    margin-bottom: 8px;
    font-size: 0.95rem;
}

.input-group {
    position: relative;
    display: flex;
}

.form-control {
    flex: 1;
    background-color: var(--input-bg);
    color: var(--text-color);
    border: 1px solid var(--input-border);
    border-radius: 10px 0 0 10px;
    padding: 12px 14px 12px 42px;
    font-size: 1rem;
    width: 100%;
    outline: none;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.form-control:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px color-mix(in srgb, var(--primary) 25%, transparent);
}

.input-icon {
    position: absolute;
    left: 14px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--muted-color);
    z-index: 2;
    display: inline-flex;
    pointer-events: none;
}

.btn-toggle-visibility {
    background-color: var(--input-bg);
    color: var(--muted-color);
    border: 1px solid var(--input-border);
    border-left: none;
    border-radius: 0 10px 10px 0;
    padding: 0 14px;
    cursor: pointer;
    transition: color 0.2s ease;
    min-width: 44px;
}

.btn-toggle-visibility:hover {
    color: var(--primary);
}

.error-text {
    color: var(--danger);
    font-size: 0.9rem;
    margin-top: 8px;
    min-height: 1.2rem;
}

/* ---------- 空状态 ---------- */
.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: var(--muted-color);
}

.empty-illustration {
    width: 64px;
    height: 64px;
    margin: 0 auto 16px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    box-shadow: 0 8px 24px color-mix(in srgb, var(--primary) 30%, transparent);
}

.empty-title {
    font-size: 1.05rem;
    font-weight: 500;
    color: var(--text-color);
    margin: 0 0 6px;
}

.empty-hint {
    font-size: 0.875rem;
    margin: 0;
}

/* ---------- 验证码卡片 ---------- */
.token-card {
    cursor: pointer;
    user-select: none;
    -webkit-tap-highlight-color: transparent;
    outline: none;
}

.token-card:hover {
    transform: translateY(-1px);
    box-shadow: 0 8px 28px rgba(20, 24, 50, 0.12);
}

.token-card:focus-visible {
    box-shadow: 0 0 0 3px color-mix(in srgb, var(--primary) 40%, transparent);
}

.token-card.copied {
    animation: copyFlash 0.6s ease;
}

@keyframes copyFlash {
    0%, 100% { box-shadow: var(--shadow-card); }
    30%      { box-shadow: 0 0 0 3px color-mix(in srgb, var(--success) 60%, transparent), var(--shadow-card); }
}

.account-meta {
    text-align: center;
    margin-bottom: 16px;
    min-height: 1.2rem;
    font-size: 0.95rem;
}

.account-meta:empty,
.account-meta.is-empty {
    display: none;
}

.account-issuer {
    font-weight: 700;
    color: var(--text-color);
}

.account-label {
    color: var(--muted-color);
    margin-left: 6px;
}

.token-display {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 14px;
    padding: 8px 0 4px;
}

/* ---------- 环形进度条 ---------- */
.ring-wrapper {
    position: relative;
    width: 220px;
    height: 220px;
}

.ring {
    width: 100%;
    height: 100%;
    transform: rotate(-90deg);
}

.ring-track {
    fill: none;
    stroke: var(--ring-track);
    stroke-width: 6;
}

.ring-progress {
    fill: none;
    stroke: var(--timer-color);
    stroke-width: 6;
    stroke-linecap: round;
    /* 周长 = 2π × 54 ≈ 339.292，由 JS 设置 stroke-dashoffset */
    stroke-dasharray: 339.292;
    stroke-dashoffset: 0;
    transition: stroke 0.3s ease;
    will-change: stroke-dashoffset;
}

.ring-content {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 6px;
}

.token-code {
    font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
    font-size: 2rem;             /* 32px，比之前 48px 小 */
    font-weight: 700;
    letter-spacing: 2px;
    color: var(--primary);
    line-height: 1;
}

.token-code.flip {
    animation: flipIn 0.4s ease;
}

@keyframes flipIn {
    0%   { transform: rotateX(80deg); opacity: 0; }
    100% { transform: rotateX(0);     opacity: 1; }
}

.token-meta {
    color: var(--muted-color);
    font-size: 0.85rem;
    font-variant-numeric: tabular-nums;
}

.token-meta #secondsRemaining {
    color: var(--timer-color);
    font-weight: 600;
    transition: color 0.3s ease;
}

/* ---------- 复制提示 ---------- */
.token-hint {
    position: relative;
    font-size: 0.85rem;
    color: var(--muted-color);
    height: 1.4em;
    width: 100%;
    line-height: 1.4em;
}

.hint-default,
.hint-success {
    position: absolute;
    inset: 0;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    white-space: nowrap;
    transition: opacity 0.25s ease, transform 0.25s ease;
}

.hint-success {
    color: var(--success);
    opacity: 0;
    transform: translateY(4px);
}

.hint-success .icon {
    width: 0.95em;
    height: 0.95em;
}

.token-card.copied .hint-default {
    opacity: 0;
    transform: translateY(-4px);
}

.token-card.copied .hint-success {
    opacity: 1;
    transform: translateY(0);
}

/* ---------- 页脚 ---------- */
.footer {
    text-align: center;
    padding: 16px 0;
    font-size: 0.85rem;
    color: var(--footer-color);
    border-top: 1px solid var(--border-color);
    margin-top: auto;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    flex-wrap: wrap;
}

.footer span {
    white-space: nowrap;
}

/* ---------- Toast ---------- */
.toast {
    position: fixed;
    top: max(20px, env(safe-area-inset-top));
    left: 50%;
    transform: translateX(-50%) translateY(-20px);
    background-color: var(--primary);
    color: white;
    padding: 10px 18px;
    border-radius: 10px;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.18);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.25s ease, transform 0.25s ease;
    z-index: 1050;
    font-size: 0.9rem;
}

.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

.toast.error {
    background-color: var(--danger);
}

/* ---------- 响应式 ---------- */
@media (max-width: 420px) {
    .ring-wrapper {
        width: 200px;
        height: 200px;
    }
    .token-code {
        font-size: 1.75rem;
        letter-spacing: 1.5px;
    }
}

/* 减少动效 */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}