/* ===== CSS Variables ===== */
:root {
    --bg:           #f0f2f5;
    --surface:      #ffffff;
    --surface-alt:  #fafbff;
    --text:         #1a1a2e;
    --text-muted:   #666;
    --text-faint:   #999;
    --border:       #dde1e9;
    --border-card:  #eef0f5;
    --border-hover: #c7d0f8;
    --accent:       #4361ee;
    --accent-dark:  #3451d1;
    --accent-bg:    #eef1ff;
    --accent-glow:  rgba(67,97,238,0.12);
    --hover-bg:     #f0f2f5;
    --header-bg:    #1a1a2e;
    --shadow:       0 1px 4px rgba(0,0,0,0.08);
    --shadow-lg:    0 20px 60px rgba(0,0,0,0.2);
    --error-bg:     #fff0f0;
    --error-border: #fca5a5;
    --error-text:   #dc2626;
    --del-border:   #fca5a5;
    --del-text:     #dc2626;
    --del-hover-bg: #dc2626;
    --overlay:      rgba(0,0,0,0.45);
    --footer-text:  #bbb;
    --toggle-bg:    rgba(255,255,255,0.1);
    --toggle-hover: rgba(255,255,255,0.2);
    --toggle-border:rgba(255,255,255,0.15);
}

[data-theme="dark"] {
    --bg:           #0d0f18;
    --surface:      #161929;
    --surface-alt:  #1a1d2e;
    --text:         #e2e8f0;
    --text-muted:   #94a3b8;
    --text-faint:   #64748b;
    --border:       #2d3348;
    --border-card:  #232740;
    --border-hover: #4361ee;
    --accent:       #6b8aff;
    --accent-dark:  #4361ee;
    --accent-bg:    #1e2545;
    --accent-glow:  rgba(107,138,255,0.15);
    --hover-bg:     #1a1d2e;
    --header-bg:    #080a12;
    --shadow:       0 1px 4px rgba(0,0,0,0.35);
    --shadow-lg:    0 20px 60px rgba(0,0,0,0.6);
    --error-bg:     #2d1515;
    --error-border: #7f1d1d;
    --error-text:   #fca5a5;
    --del-border:   #7f1d1d;
    --del-text:     #fca5a5;
    --del-hover-bg: #b91c1c;
    --overlay:      rgba(0,0,0,0.65);
    --footer-text:  #3d4a60;
    --toggle-bg:    rgba(255,255,255,0.06);
    --toggle-hover: rgba(255,255,255,0.12);
    --toggle-border:rgba(255,255,255,0.1);
}

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

html {
    color-scheme: light dark;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: background 0.25s, color 0.25s;
}

/* ===== Header ===== */
header {
    background: var(--header-bg);
    color: #fff;
    padding: 0.85rem 2rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.25);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}

header h1 {
    font-size: 1.35rem;
    font-weight: 600;
    letter-spacing: 0.02em;
}

/* ===== Header actions (toggle + logout) ===== */
.header-actions {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-shrink: 0;
}

.btn-logout {
    background: rgba(255,255,255,0.08);
    border: 1px solid rgba(255,255,255,0.15);
    color: rgba(255,255,255,0.75);
    border-radius: 8px;
    padding: 0.4rem 0.8rem;
    font-size: 0.85rem;
    font-family: inherit;
    cursor: pointer;
    text-decoration: none;
    white-space: nowrap;
    transition: background 0.2s, color 0.2s;
}

.btn-logout:hover {
    background: rgba(220,38,38,0.35);
    border-color: rgba(220,38,38,0.5);
    color: #fff;
}

/* ===== Dark Mode Toggle ===== */
.theme-toggle {
    background: var(--toggle-bg);
    border: 1px solid var(--toggle-border);
    color: #fff;
    border-radius: 8px;
    padding: 0.4rem 0.8rem;
    font-size: 0.85rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.4rem;
    transition: background 0.2s;
    white-space: nowrap;
    flex-shrink: 0;
}

.theme-toggle:hover {
    background: var(--toggle-hover);
}

/* ===== Layout ===== */
.container {
    display: flex;
    gap: 1.5rem;
    max-width: 1000px;
    width: 100%;
    margin: 2rem auto;
    padding: 0 1rem;
    flex: 1;
    align-items: flex-start;
}

/* ===== Sidebar ===== */
.sidebar {
    width: 200px;
    flex-shrink: 0;
    background: var(--surface);
    border-radius: 10px;
    padding: 1.25rem;
    box-shadow: var(--shadow);
    transition: background 0.25s;
}

.sidebar h3 {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-faint);
    margin-bottom: 0.75rem;
}

.sidebar ul {
    list-style: none;
}

.sidebar ul li + li {
    margin-top: 0.25rem;
}

.sidebar ul li a {
    display: block;
    padding: 0.5rem 0.75rem;
    border-radius: 6px;
    color: var(--text);
    text-decoration: none;
    font-size: 0.9rem;
    transition: background 0.15s, color 0.15s;
}

.sidebar ul li a:hover {
    background: var(--hover-bg);
    color: var(--accent);
}

.sidebar ul li a.active {
    background: var(--accent-bg);
    color: var(--accent);
    font-weight: 600;
}

/* ===== Main Content ===== */
.main-content {
    flex: 1;
    background: var(--surface);
    border-radius: 10px;
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: background 0.25s;
}

.main-content h2 {
    font-size: 1.4rem;
    margin-bottom: 0.4rem;
    color: var(--text);
}

.main-content > p {
    color: var(--text-muted);
    margin-bottom: 1.75rem;
    font-size: 0.95rem;
}

/* ===== Form ===== */
.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-muted);
    margin-bottom: 0.4rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.65rem 0.9rem;
    border: 1.5px solid var(--border);
    border-radius: 7px;
    font-size: 0.95rem;
    font-family: inherit;
    color: var(--text);
    background: var(--surface-alt);
    transition: border-color 0.2s, box-shadow 0.2s, background 0.25s;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
    background: var(--surface);
}

.form-group textarea {
    height: 140px;
    resize: vertical;
}

.form-error {
    background: var(--error-bg);
    border: 1px solid var(--error-border);
    color: var(--error-text);
    border-radius: 7px;
    padding: 0.65rem 0.9rem;
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

.form-error.hidden { display: none; }

button[type="submit"] {
    background: var(--accent);
    color: #fff;
    border: none;
    padding: 0.7rem 1.75rem;
    border-radius: 7px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s, transform 0.1s;
}

button[type="submit"]:hover:not(:disabled) { background: var(--accent-dark); }
button[type="submit"]:active:not(:disabled) { transform: scale(0.98); }
button[type="submit"]:disabled { opacity: 0.6; cursor: not-allowed; }

/* ===== Thank You Modal ===== */
.modal {
    position: fixed;
    inset: 0;
    background: var(--overlay);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    animation: fadeIn 0.2s ease;
}

.modal.hidden { display: none; }

@keyframes fadeIn {
    from { opacity: 0; }
    to   { opacity: 1; }
}

.modal-box {
    background: var(--surface);
    border-radius: 14px;
    padding: 2.5rem 2rem;
    text-align: center;
    max-width: 380px;
    width: 90%;
    box-shadow: var(--shadow-lg);
    animation: slideUp 0.25s ease;
}

@keyframes slideUp {
    from { transform: translateY(20px); opacity: 0; }
    to   { transform: translateY(0);    opacity: 1; }
}

.modal-icon {
    width: 56px;
    height: 56px;
    background: var(--accent);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.6rem;
    margin: 0 auto 1.25rem;
}

.modal-box h2 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text);
}

.modal-box p {
    color: var(--text-muted);
    line-height: 1.6;
    margin-bottom: 1.75rem;
    font-size: 0.95rem;
}

.modal-box button {
    background: var(--accent);
    color: #fff;
    border: none;
    padding: 0.65rem 2rem;
    border-radius: 7px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
}

.modal-box button:hover { background: var(--accent-dark); }

/* ===== Archive toolbar ===== */
.archive-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    margin-bottom: 1.25rem;
    flex-wrap: wrap;
}

.archive-count {
    color: var(--text-faint);
    font-size: 0.85rem;
    font-weight: 500;
    white-space: nowrap;
}

/* Search input with embedded icon */
.search-input {
    flex: 1;
    min-width: 180px;
    max-width: 300px;
    padding: 0.55rem 0.9rem 0.55rem 2.1rem;
    border: 1.5px solid var(--border);
    border-radius: 7px;
    font-size: 0.875rem;
    font-family: inherit;
    color: var(--text);
    background-color: var(--surface-alt);
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20' fill='%23999999'%3E%3Cpath fill-rule='evenodd' d='M9 3a6 6 0 100 12A6 6 0 009 3zM1 9a8 8 0 1114.32 4.906l3.387 3.387a1 1 0 01-1.414 1.414l-3.387-3.387A8 8 0 011 9z' clip-rule='evenodd'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: 0.65rem center;
    background-size: 14px;
    transition: border-color 0.2s, box-shadow 0.2s, background-color 0.25s;
}

.search-input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
    background-color: var(--surface);
}

.no-results {
    color: var(--text-faint);
    font-size: 0.9rem;
    padding: 1.5rem 0;
    text-align: center;
}

.no-results.hidden { display: none; }

/* ===== Message cards ===== */
.empty-state {
    color: var(--text-muted);
    font-size: 0.95rem;
    padding: 2rem 0;
}

.empty-state a {
    color: var(--accent);
    text-decoration: none;
}

.messages-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.message-card {
    border: 1.5px solid var(--border-card);
    border-radius: 10px;
    padding: 1rem 1.25rem;
    background: var(--surface);
    transition: border-color 0.2s, background 0.25s;
}

.message-card:hover {
    border-color: var(--border-hover);
}

.message-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.65rem;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.message-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.message-email {
    font-weight: 600;
    color: var(--accent);
    font-size: 0.9rem;
}

.message-date {
    font-size: 0.78rem;
    color: var(--text-faint);
}

/* Delete button */
.btn-delete {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    background: none;
    border: 1.5px solid var(--del-border);
    color: var(--del-text);
    border-radius: 6px;
    padding: 0.28rem 0.65rem;
    font-size: 0.78rem;
    font-family: inherit;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.15s, color 0.15s, border-color 0.15s;
    white-space: nowrap;
}

.btn-delete svg {
    width: 12px !important;
    height: 12px !important;
    flex-shrink: 0;
}

.btn-delete:hover:not(:disabled) {
    background: var(--del-hover-bg);
    color: #fff;
    border-color: var(--del-hover-bg);
}

.btn-delete:disabled {
    opacity: 0.45;
    cursor: not-allowed;
}

.message-body {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.65;
}

/* ===== Footer ===== */
footer {
    text-align: center;
    padding: 1.5rem;
    color: var(--footer-text);
    font-size: 0.8rem;
    transition: color 0.25s;
}

/* ===== Responsive ===== */
@media (max-width: 640px) {
    .container { flex-direction: column; }
    .sidebar { width: 100%; }
    .sidebar ul { display: flex; gap: 0.5rem; }
    .sidebar ul li + li { margin-top: 0; }
    .search-wrap { max-width: 100%; }
}