:root { color-scheme: light; font-family: Inter, "Microsoft YaHei", system-ui, sans-serif; color: #18202b; background: #f2f5f8; }
* { box-sizing: border-box; }
body { margin: 0; min-height: 100vh; }
.shell { max-width: 1320px; margin: 0 auto; padding: 32px 24px 48px; }
h1, h2, p { margin-top: 0; }
h1 { margin-bottom: 6px; font-size: 25px; letter-spacing: -.03em; }
h2 { margin: 0; font-size: 17px; }
p { color: #6b7482; margin-bottom: 0; }
.eyebrow { color: #5574d9; font-size: 11px; font-weight: 750; letter-spacing: .16em; margin-bottom: 8px; }
.card { background: #fff; border: 1px solid #e2e7ee; border-radius: 14px; box-shadow: 0 5px 20px #17263b08; }
.hidden { display: none !important; }
.login { width: min(420px, 100%); margin: 12vh auto; padding: 34px; }
form { margin-top: 24px; display: grid; gap: 10px; }
label { font-size: 13px; font-weight: 650; }
input { min-width: 0; border: 1px solid #d8dee8; border-radius: 8px; padding: 12px; font: inherit; outline: none; }
input:focus { border-color: #5574d9; box-shadow: 0 0 0 3px #5574d921; }
button { border: 0; background: #3159ca; color: #fff; border-radius: 8px; padding: 11px 15px; font: inherit; font-weight: 650; cursor: pointer; }
button:hover { background: #2649ad; }
button:disabled { opacity: .55; cursor: wait; }
.quiet { background: transparent; color: #506074; padding: 8px 10px; }
.quiet:hover { background: #f2f5f9; color: #26354a; }
.error { color: #b42318; min-height: 20px; font-size: 13px; }
.topbar { display: flex; align-items: center; justify-content: space-between; margin-bottom: 22px; }
.layout { display: grid; grid-template-columns: minmax(320px, 430px) 1fr; gap: 18px; min-height: 70vh; }
.list-panel { padding: 18px; display: flex; flex-direction: column; }
.list-heading { display: flex; align-items: center; justify-content: space-between; padding: 0 2px 12px; border-bottom: 1px solid #edf0f4; }
.status { color: #7a8492; font-size: 12px; padding: 11px 3px 6px; }
.messages { display: grid; align-content: start; }
.message { padding: 13px 10px; border-bottom: 1px solid #edf0f4; cursor: pointer; border-radius: 8px; }
.message:hover, .message.selected { background: #f2f6ff; }
.message-top { display: flex; justify-content: space-between; gap: 12px; }
.sender { font-size: 13px; font-weight: 700; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.date { color: #858f9e; font-size: 11px; flex: none; }
.subject { margin-top: 5px; font-size: 13px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.recipient { margin-top: 5px; color: #87909d; font-size: 11px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.more { background: #f3f6fb; color: #4b5d78; margin-top: 14px; }
.detail { padding: 26px; min-width: 0; }
.detail.empty { display: grid; place-items: center; color: #8993a0; }
.empty-state { text-align: center; }
.mail-head { padding-bottom: 20px; border-bottom: 1px solid #edf0f4; }
.mail-head h2 { margin: 0 0 17px; font-size: 21px; overflow-wrap: anywhere; }
.mail-meta { display: grid; gap: 7px; color: #667181; font-size: 12px; overflow-wrap: anywhere; }
.mail-meta strong { color: #374151; font-weight: 650; }
.mail-tools { display: flex; justify-content: flex-end; margin-top: 12px; }
.body-text { white-space: pre-wrap; overflow-wrap: anywhere; line-height: 1.65; font-size: 14px; padding-top: 20px; color: #303a49; }
.attachments { margin-top: 18px; padding-top: 14px; border-top: 1px solid #edf0f4; color: #6b7482; font-size: 12px; }
.attachment { padding: 4px 0; }
@media (max-width: 800px) { .shell { padding: 20px 12px; } .layout { grid-template-columns: 1fr; } .detail { min-height: 42vh; } .topbar { align-items: flex-start; } }